Cryptorush rep "linkandzelda" said the thieves took advantage of a glitch at the exchange involving accounts holding BlackCoin, a proof-of digital currency, he said. User balances at the exchange were accidentally inflated to an extra 22 million coins, allowing them to withdraw more than they had.

"We'll post more when we know how we can pay back affected users or get some compensation for this massive massive loss," linkandzelda wrote. "100 BTC doesn't just come out of thin air, so please be patient while we make this right."

CryptoRush customers have been quick to blame CryptoRush for the glitch. "The only chance this exchange has any chance now at surviving... is to make a public statement of apology AND return all funds (even if using money earned from the trades)," wrote Bitcointalk user "mybougsname". "It would be tedious, but worthwhile to manually go thru the logs and see who withdrew to many coins."